Conventionally, there are used many disk cartridges housing a disk-shaped recording medium such as an optical disk or the like rotatably in it and which can be loaded into a disk drive unit while holding the disk-shaped recording medium encased in it. The disk cartridge of this type houses in a body thereof a disk-shaped recording medium to protect the latter, and permits easy insertion and ejection of the disk-shaped recording medium into and out of the disk drive unit. Many of the conventional disk cartridges of this type are ones each housing a disk-shaped recording medium rotatably in a rectangular body thereof.
Note here that the disk cartridge is required to have a design as compact as possible correspondingly to the size of a disk shaped recording medium to be housed in the cartridge body. This is intended to design smaller a disk recording and/or playback apparatus using the disk cartridge and make easier handling of the disk cartridge as well as to minimize the material and manufacturing cost of the disk cartridge.
A disk cartridge designed smaller correspondingly to the size of a disk-shaped recording medium to be housed is known from the disclosure in the Japanese Patent Application Laid Open No. 353845 of 1999. This conventional disk cartridge itself is designed small by forming generally circular one lateral side thereof at which it is first inserted into the recording and/or playback apparatus. The disk cartridge disclosed in the above-mentioned Japanese Patent Application Laid Open No. 353845 of 1999 has formed in a body thereof in which an optical disk is encased a write and/or read opening (will be referred to as “write/read opening” or “head opening” hereunder) which is to be covered and uncovered by a shutter member and through which a part of the optical disk can be exposed to outside. Information signals are written to, or read from, the optical disk with an optical pickup included in a write/read head being placed to face the optical disk exposed to outside of the cartridge body through the write/read opening.
The recording and/or playback apparatus using the disk cartridge as a recording medium is designed such that with the optical pickup being moved radially of the optical disk while being kept at a distance from the disk cartridge, the signal recording area on the optical disk is scanned to write or read information signals to or from the optical disk. Since in the recording and/or playback apparatus for writing or reading information signals to or from the optical disk as above, the optical pickup is moved while being kept at a distance from the disk cartridge, it is difficult to design the apparatus thinner.